<!DOCTYPE html><html lang="zh-CN" data-theme="light"><head><meta charset="UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no"><title>Java常见集合类型对比 | 樱桃小窝</title><meta name="keywords" content="集合框架,Java基础"><meta name="author" content="樱桃先生"><meta name="copyright" content="樱桃先生"><meta name="format-detection" content="telephone=no"><meta name="theme-color" content="#ffffff"><meta name="description" content="Java常见集合类型对比   List 和 Set 区别 List, Set 都是继承自 Collection 接口 List 特点：元素有放入顺序，元素可重复。Set 特点：元素无放入顺序，元素不可重复（注意：元素虽然无放入顺序，但是元素在 set 中的位置是有该元素的 HashCode 决定的，其位置其实是固定的） List 接口有三个实现类：LinkedList，ArrayList，Vect">
<meta property="og:type" content="article">
<meta property="og:title" content="Java常见集合类型对比">
<meta property="og:url" content="http://example.com/posts/dd8469b9/index.html">
<meta property="og:site_name" content="樱桃小窝">
<meta property="og:description" content="Java常见集合类型对比   List 和 Set 区别 List, Set 都是继承自 Collection 接口 List 特点：元素有放入顺序，元素可重复。Set 特点：元素无放入顺序，元素不可重复（注意：元素虽然无放入顺序，但是元素在 set 中的位置是有该元素的 HashCode 决定的，其位置其实是固定的） List 接口有三个实现类：LinkedList，ArrayList，Vect">
<meta property="og:locale" content="zh_CN">
<meta property="og:image" content="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png">
<meta property="article:published_time" content="2020-09-13T07:04:00.000Z">
<meta property="article:modified_time" content="2022-08-27T09:47:57.623Z">
<meta property="article:author" content="樱桃先生">
<meta property="article:tag" content="集合框架">
<meta property="article:tag" content="Java基础">
<meta name="twitter:card" content="summary">
<meta name="twitter:image" content="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png"><link rel="shortcut icon" href="/img/favicon.png"><link rel="canonical" href="http://example.com/posts/dd8469b9/"><link rel="preconnect" href="//cdn.jsdelivr.net"/><link rel="preconnect" href="//busuanzi.ibruce.info"/><link rel="stylesheet" href="/css/index.css"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@fortawesome/fontawesome-free/css/all.min.css" media="print" onload="this.media='all'"><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@fancyapps/ui/dist/fancybox.min.css" media="print" onload="this.media='all'"><script>const GLOBAL_CONFIG = { 
  root: '/',
  algolia: undefined,
  localSearch: undefined,
  translate: undefined,
  noticeOutdate: undefined,
  highlight: {"plugin":"highlighjs","highlightCopy":true,"highlightLang":true,"highlightHeightLimit":false},
  copy: {
    success: '复制成功',
    error: '复制错误',
    noSupport: '浏览器不支持'
  },
  relativeDate: {
    homepage: false,
    post: false
  },
  runtime: '天',
  date_suffix: {
    just: '刚刚',
    min: '分钟前',
    hour: '小时前',
    day: '天前',
    month: '个月前'
  },
  copyright: undefined,
  lightbox: 'fancybox',
  Snackbar: undefined,
  source: {
    justifiedGallery: {
      js: 'https://cdn.jsdelivr.net/npm/flickr-justified-gallery/dist/fjGallery.min.js',
      css: 'https://cdn.jsdelivr.net/npm/flickr-justified-gallery/dist/fjGallery.min.css'
    }
  },
  isPhotoFigcaption: false,
  islazyload: true,
  isAnchor: false
}</script><script id="config-diff">var GLOBAL_CONFIG_SITE = {
  title: 'Java常见集合类型对比',
  isPost: true,
  isHome: false,
  isHighlightShrink: false,
  isToc: true,
  postUpdate: '2022-08-27 17:47:57'
}</script><noscript><style type="text/css">
  #nav {
    opacity: 1
  }
  .justified-gallery img {
    opacity: 1
  }

  #recent-posts time,
  #post-meta time {
    display: inline !important
  }
</style></noscript><script>(win=>{
    win.saveToLocal = {
      set: function setWithExpiry(key, value, ttl) {
        if (ttl === 0) return
        const now = new Date()
        const expiryDay = ttl * 86400000
        const item = {
          value: value,
          expiry: now.getTime() + expiryDay,
        }
        localStorage.setItem(key, JSON.stringify(item))
      },

      get: function getWithExpiry(key) {
        const itemStr = localStorage.getItem(key)

        if (!itemStr) {
          return undefined
        }
        const item = JSON.parse(itemStr)
        const now = new Date()

        if (now.getTime() > item.expiry) {
          localStorage.removeItem(key)
          return undefined
        }
        return item.value
      }
    }
  
    win.getScript = url => new Promise((resolve, reject) => {
      const script = document.createElement('script')
      script.src = url
      script.async = true
      script.onerror = reject
      script.onload = script.onreadystatechange = function() {
        const loadState = this.readyState
        if (loadState && loadState !== 'loaded' && loadState !== 'complete') return
        script.onload = script.onreadystatechange = null
        resolve()
      }
      document.head.appendChild(script)
    })
  
      win.activateDarkMode = function () {
        document.documentElement.setAttribute('data-theme', 'dark')
        if (document.querySelector('meta[name="theme-color"]') !== null) {
          document.querySelector('meta[name="theme-color"]').setAttribute('content', '#0d0d0d')
        }
      }
      win.activateLightMode = function () {
        document.documentElement.setAttribute('data-theme', 'light')
        if (document.querySelector('meta[name="theme-color"]') !== null) {
          document.querySelector('meta[name="theme-color"]').setAttribute('content', '#ffffff')
        }
      }
      const t = saveToLocal.get('theme')
    
          if (t === 'dark') activateDarkMode()
          else if (t === 'light') activateLightMode()
        
      const asideStatus = saveToLocal.get('aside-status')
      if (asideStatus !== undefined) {
        if (asideStatus === 'hide') {
          document.documentElement.classList.add('hide-aside')
        } else {
          document.documentElement.classList.remove('hide-aside')
        }
      }
    
    const detectApple = () => {
      if(/iPad|iPhone|iPod|Macintosh/.test(navigator.userAgent)){
        document.documentElement.classList.add('apple')
      }
    }
    detectApple()
    })(window)</script><meta name="generator" content="Hexo 5.4.2"></head><body><div id="sidebar"><div id="menu-mask"></div><div id="sidebar-menus"><div class="avatar-img is-center"><img src= "" data-lazy-src="https://s2.loli.net/2022/08/20/hk9Zvq4YRsIcnrw.jpg" onerror="onerror=null;src='/img/friend_404.gif'" alt="avatar"/></div><div class="sidebar-site-data site-data is-center"><a href="/archives/"><div class="headline">文章</div><div class="length-num">78</div></a><a href="/tags/"><div class="headline">标签</div><div class="length-num">65</div></a><a href="/categories/"><div class="headline">分类</div><div class="length-num">21</div></a></div><hr/><div class="menus_items"><div class="menus_item"><a class="site-page" href="/"><i class="fa-fw fas fa-home"></i><span> 主页</span></a></div><div class="menus_item"><a class="site-page" href="/archives/"><i class="fa-fw fas fa-archive"></i><span> 时间线</span></a></div><div class="menus_item"><a class="site-page" href="/categories/"><i class="fa-fw fas fa-folder-open"></i><span> 分类</span></a></div><div class="menus_item"><a class="site-page" href="/tags/"><i class="fa-fw fas fa-tags"></i><span> 标签</span></a></div><div class="menus_item"><a class="site-page" href="/gallery/"><i class="fa-fw fas fa-camera"></i><span> 图库</span></a></div><div class="menus_item"><a class="site-page" href="/messageboard/"><i class="fa-fw fas fa-comment-dots"></i><span> 留言板</span></a></div><div class="menus_item"><a class="site-page" href="/links/"><i class="fa-fw fas fa-link"></i><span> 友链</span></a></div><div class="menus_item"><a class="site-page" href="/about/"><i class="fa-fw fas fa-heart"></i><span> 关于</span></a></div></div></div></div><div class="post" id="body-wrap"><header class="post-bg" id="page-header" style="background-image: url('https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png')"><nav id="nav"><span id="blog_name"><a id="site-name" href="/">樱桃小窝</a></span><div id="menus"><div class="menus_items"><div class="menus_item"><a class="site-page" href="/"><i class="fa-fw fas fa-home"></i><span> 主页</span></a></div><div class="menus_item"><a class="site-page" href="/archives/"><i class="fa-fw fas fa-archive"></i><span> 时间线</span></a></div><div class="menus_item"><a class="site-page" href="/categories/"><i class="fa-fw fas fa-folder-open"></i><span> 分类</span></a></div><div class="menus_item"><a class="site-page" href="/tags/"><i class="fa-fw fas fa-tags"></i><span> 标签</span></a></div><div class="menus_item"><a class="site-page" href="/gallery/"><i class="fa-fw fas fa-camera"></i><span> 图库</span></a></div><div class="menus_item"><a class="site-page" href="/messageboard/"><i class="fa-fw fas fa-comment-dots"></i><span> 留言板</span></a></div><div class="menus_item"><a class="site-page" href="/links/"><i class="fa-fw fas fa-link"></i><span> 友链</span></a></div><div class="menus_item"><a class="site-page" href="/about/"><i class="fa-fw fas fa-heart"></i><span> 关于</span></a></div></div><div id="toggle-menu"><a class="site-page"><i class="fas fa-bars fa-fw"></i></a></div></div></nav><div id="post-info"><h1 class="post-title">Java常见集合类型对比</h1><div id="post-meta"><div class="meta-firstline"><span class="post-meta-date"><i class="far fa-calendar-alt fa-fw post-meta-icon"></i><span class="post-meta-label">发表于</span><time class="post-meta-date-created" datetime="2020-09-13T07:04:00.000Z" title="发表于 2020-09-13 15:04:00">2020-09-13</time><span class="post-meta-separator">|</span><i class="fas fa-history fa-fw post-meta-icon"></i><span class="post-meta-label">更新于</span><time class="post-meta-date-updated" datetime="2022-08-27T09:47:57.623Z" title="更新于 2022-08-27 17:47:57">2022-08-27</time></span><span class="post-meta-categories"><span class="post-meta-separator">|</span><i class="fas fa-inbox fa-fw post-meta-icon"></i><a class="post-meta-categories" href="/categories/%E6%8A%80%E6%9C%AF/">技术</a><i class="fas fa-angle-right post-meta-separator"></i><i class="fas fa-inbox fa-fw post-meta-icon"></i><a class="post-meta-categories" href="/categories/%E6%8A%80%E6%9C%AF/Java/">Java</a></span></div><div class="meta-secondline"><span class="post-meta-separator">|</span><span class="post-meta-pv-cv" id="" data-flag-title="Java常见集合类型对比"><i class="far fa-eye fa-fw post-meta-icon"></i><span class="post-meta-label">阅读量:</span><span id="busuanzi_value_page_pv"><i class="fa-solid fa-spinner fa-spin"></i></span></span></div></div></div></header><main class="layout" id="content-inner"><div id="post"><article class="post-content" id="article-container"><h1 id="Java常见集合类型对比"><a href="#Java常见集合类型对比" class="headerlink" title="Java常见集合类型对比"></a>Java常见集合类型对比</h1><p><img src= "" data-lazy-src="https://gitee.com/xyingtao/blogimage/raw/master/img/List%E5%B8%B8%E7%94%A8%E6%96%B9%E6%B3%95.png" alt="List常用方法"></p>
<p><img src= "" data-lazy-src="https://gitee.com/xyingtao/blogimage/raw/master/img/Map%E5%B8%B8%E7%94%A8%E6%96%B9%E6%B3%95.png" alt="Map常用方法"></p>
<p><img src= "" data-lazy-src="https://gitee.com/xyingtao/blogimage/raw/master/img/Set%E5%B8%B8%E7%94%A8%E6%96%B9%E6%B3%95.png" alt="Set常用方法"></p>
<h2 id="List-和-Set-区别"><a href="#List-和-Set-区别" class="headerlink" title="List 和 Set 区别"></a>List 和 Set 区别</h2><ul>
<li>List, Set 都是继承自 Collection 接口</li>
<li>List 特点：元素有放入顺序，元素可重复。Set 特点：元素无放入顺序，元素不可重复（注意：元素虽然无放入顺序，但是元素在 set 中的位置是有该元素的 HashCode 决定的，其位置其实是固定的）</li>
<li>List 接口有三个实现类：LinkedList，ArrayList，Vector。Set 接口有两个实现类：HashSet(底层由 HashMap 实现)，LinkedHashSet</li>
</ul>
<h2 id="List-和-Map-区别"><a href="#List-和-Map-区别" class="headerlink" title="List 和 Map 区别"></a>List 和 Map 区别</h2><ul>
<li>List 特点：元素有放入顺序，元素可重复;</li>
<li>Map 特点：元素按键值对存储，无放入顺序 ;</li>
<li>List 接口有三个实现类：LinkedList，ArrayList，Vector;</li>
<li>LinkedList：底层基于链表实现，链表内存是散乱的，每一个元素存储本身内存地址的同时还存储下一个元素的地址。<strong>链表增删快，查找慢</strong>;</li>
<li>Map 接口有三个实现类：HashMap，HashTable，LinkedHashMap</li>
<li>Map 相当于和 Collection 一个级别的；Map 集合存储键值对，且要求保持<strong>键</strong>的唯一性；</li>
</ul>
<h2 id="ArrayList-与-LinkedList-区别"><a href="#ArrayList-与-LinkedList-区别" class="headerlink" title="ArrayList 与 LinkedList 区别"></a>ArrayList 与 LinkedList 区别</h2><ul>
<li>因为 Array 是基于索引(index)的数据结构，它使用索引在数组中<strong>搜索和读取数据</strong>是很快的。Array 获取数据的时间复杂度是 <code>O(1)</code>,但是要<strong>删除数据却是开销很大</strong>的，因为这需要重排数组中的所有数据。</li>
<li>相对于 ArrayList，LinkedList 插入是更快的。因为 LinkedList 不像 ArrayList 一样，不需要改变数组的大小，也不需要在数组装满的时候要将所有的数据重新装入一个新的数组，这是 ArrayList 最坏的一种情况，时间复杂度是 <code>O(n)</code>，而 LinkedList 中插入或删除的时间复杂度仅为 <code>O(1)</code>。ArrayList 在插入数据时还需要更新索引（除了插入数组的尾部）。</li>
<li>类似于插入数据，删除数据时，LinkedList 也优于 ArrayList。</li>
<li>LinkedList 需要更多的内存，因为 ArrayList 的每个索引的位置是实际的数据，而 LinkedList 中的每个节点中存储的是实际的数据和<strong>前后节点</strong>的位置。</li>
<li>你的应用不会随机访问数据。因为如果你需要 LinkedList 中的第 n 个元素的时候，你需要从第一个元素顺序数到第 n 个数据，然后读取数据。</li>
<li>你的应用更多的插入和删除元素，更少的读取数据。因为插入和删除元素不涉及重排数据，所以它要比 ArrayList 要快。</li>
</ul>
<h2 id="ArrayList-与-Vector-区别"><a href="#ArrayList-与-Vector-区别" class="headerlink" title="ArrayList 与 Vector 区别"></a>ArrayList 与 Vector 区别</h2><ul>
<li>同步性：Vector 是线程安全的，也就是说是同步的 ，而 ArrayList 是线程不安全的，不是同步的。</li>
<li>数据增长：当需要增长时，Vector 默认增长为原来一倍 ，而 ArrayList 却是原来的 50% ，这样 ArrayList 就有利于节约内存空间。</li>
</ul>
<p>说明：如果涉及到堆栈，队列等操作，应该考虑用 Vector，如果需要快速随机访问元素，应该使用 ArrayList</p>
<h2 id="HashMap-和-HashTable-的区别"><a href="#HashMap-和-HashTable-的区别" class="headerlink" title="HashMap 和 HashTable 的区别"></a>HashMap 和 HashTable 的区别</h2><ul>
<li>HashMap 几乎可以等价于 HashTable，除了 HashMap 是<strong>非 synchronized</strong> 的，并可以接受 <strong>null</strong>(HashMap 可以接受为 null 的键值 (key) 和值 (value)，而 HashTable 则不行)。</li>
<li>HashMap 是非 synchronized，而 HashTable 是 <strong>synchronized</strong>，这意味着 HashTable 是线程安全的，多个线程可以共享一个 HashTable；而如果没有正确的同步的话，多个线程是不能共享 HashMap 的。Java 5 提供了 ConcurrentHashMap，它是 HashTable 的替代，比 HashTable 的扩展性更好。</li>
<li>另一个区别是 HashMap 的迭代器 (Iterator) 是 fail-fast 迭代器，而 HashTable 的 enumerator 迭代器不是 fail-fast 的。所以当有其它线程改变了 HashMap 的结构（增加或者移除元素），将会抛出 ConcurrentModificationException，但迭代器本身的 remove() 方法移除元素则不会抛出 ConcurrentModificationException 异常。但这并不是一个一定发生的行为，要看 JVM。这条同样也是 Enumeration 和 Iterator 的区别。</li>
<li>由于 HashTable 是线程安全的也是 synchronized，所以在单线程环境下它比 HashMap 要慢。如果你不需要同步，只需要单一线程，那么使用 HashMap 性能要好过 HashTable。</li>
<li>HashMap 不能保证随着时间的推移 Map 中的元素次序是不变的。</li>
</ul>
<h2 id="HashSet-和-HashMap-区别"><a href="#HashSet-和-HashMap-区别" class="headerlink" title="HashSet 和 HashMap 区别"></a>HashSet 和 HashMap 区别</h2><table>
<thead>
<tr>
<th>HashMap</th>
<th>HashSet</th>
</tr>
</thead>
<tbody><tr>
<td>HashMap 实现了 Map 接口</td>
<td>HashSet 实现了 Set 接口</td>
</tr>
<tr>
<td>HashMap 储存键值对</td>
<td>HashSet 仅仅存储对象</td>
</tr>
<tr>
<td>使用 put() 方法将元素放入 map 中</td>
<td>使用 add() 方法将元素放入 set 中</td>
</tr>
<tr>
<td>HashMap 中使用键对象来计算 hashcode 值</td>
<td>HashSet 使用成员对象来计算 hashcode 值，对于两个对象来说 hashcode 可能相同，所以 equals() 方法用来判断对象的相等性，如果两个对象不同的话，那么返回 false</td>
</tr>
<tr>
<td>HashMap 比较快，因为是使用唯一的键来获取对象</td>
<td>HashSet 较 HashMap 来说比较慢</td>
</tr>
</tbody></table>
<h2 id="HashMap-和-ConcurrentHashMap-的区别"><a href="#HashMap-和-ConcurrentHashMap-的区别" class="headerlink" title="HashMap 和 ConcurrentHashMap 的区别"></a>HashMap 和 ConcurrentHashMap 的区别</h2><ul>
<li>放入 HashMap 的元素是 key-value 对。</li>
<li>底层说白了就是散列结构。</li>
<li>要将元素放入到 HashMap 中，那么 key 的类型必须要实现 hashcode 方法，默认这个方法是根据对象的地址来计算的，接着还必须覆盖对象的 equals() 方法。</li>
<li>ConcurrentHashMap 对整个<strong>桶数组</strong>进行了分段，而 HashMap 则没有</li>
<li>ConcurrentHashMap 在每一个分段上都用锁进行保护，从而让锁的粒度更精细一些，并发性能更好，而 HashMap 没有锁机制，不是线程安全的</li>
</ul>
<h2 id="HashMap-的工作原理及代码实现"><a href="#HashMap-的工作原理及代码实现" class="headerlink" title="HashMap 的工作原理及代码实现"></a>HashMap 的工作原理及代码实现</h2><p>HashMap 基于 hashing 原理，我们通过 put() 和 get() 方法储存和获取对象。当我们将键值对传递给 put() 方法时，它调用键对象的 hashCode() 方法来计算 hashcode，让后找到 bucket 位置来储存值对象。当获取对象时，通过键对象的 equals() 方法找到正确的键值对，然后返回值对象。HashMap 使用链表来解决碰撞问题，当发生碰撞了，对象将会储存在链表的下一个节点中。 HashMap 在每个链表节点中储存键值对对象。</p>
<h2 id="ConcurrentHashMap-的工作原理及代码实现"><a href="#ConcurrentHashMap-的工作原理及代码实现" class="headerlink" title="ConcurrentHashMap 的工作原理及代码实现"></a>ConcurrentHashMap 的工作原理及代码实现</h2><p>ConcurrentHashMap 采用了非常精妙的”分段锁”策略，ConcurrentHashMap 的主干是个 Segment 数组。Segment 继承了 ReentrantLock，所以它就是一种可重入锁（ReentrantLock)。在 ConcurrentHashMap，一个 Segment 就是一个子哈希表，Segment 里维护了一个 HashEntry 数组，并发环境下，对于不同 Segment 的数据进行操作是不用考虑锁竞争的。</p>
<p>资料参考: 千峰网</p>
</article><div class="tag_share"><div class="post-meta__tag-list"><a class="post-meta__tags" href="/tags/%E9%9B%86%E5%90%88%E6%A1%86%E6%9E%B6/">集合框架</a><a class="post-meta__tags" href="/tags/Java%E5%9F%BA%E7%A1%80/">Java基础</a></div><div class="post_share"><div class="social-share" data-image="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png" data-sites="wechat,weibo,qq"></div><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/butterfly-extsrc/sharejs/dist/css/share.min.css" media="print" onload="this.media='all'"><script src="https://cdn.jsdelivr.net/npm/butterfly-extsrc/sharejs/dist/js/social-share.min.js" defer></script></div></div><div class="post-reward"><div class="reward-button"><i class="fas fa-qrcode"></i> 打赏</div><div class="reward-main"><ul class="reward-all"><li class="reward-item"><a href="https://s2.loli.net/2022/08/21/Ay5sujrkH1nLTwW.jpg" target="_blank"><img class="post-qr-code-img" src= "" data-lazy-src="https://s2.loli.net/2022/08/21/Ay5sujrkH1nLTwW.jpg" alt="Wechat"/></a><div class="post-qr-code-desc">Wechat</div></li></ul></div></div><nav class="pagination-post" id="pagination"><div class="prev-post pull-left"><a href="/posts/89080a8e/"><img class="prev-cover" src= "" data-lazy-src="https://gitee.com/xyingtao/blogimage/raw/master/Spring.jpg" onerror="onerror=null;src='/img/404.jpg'" alt="cover of previous post"><div class="pagination-info"><div class="label">上一篇</div><div class="prev_info">Spring Bean的生命周期</div></div></a></div><div class="next-post pull-right"><a href="/posts/fea7e8d3/"><img class="next-cover" src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png" onerror="onerror=null;src='/img/404.jpg'" alt="cover of next post"><div class="pagination-info"><div class="label">下一篇</div><div class="next_info">新的日期和时间类</div></div></a></div></nav><div class="relatedPosts"><div class="headline"><i class="fas fa-thumbs-up fa-fw"></i><span>相关推荐</span></div><div class="relatedPosts-list"><div><a href="/posts/9753a2e/" title="Java集合框架"><img class="cover" src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2021-03-04</div><div class="title">Java集合框架</div></div></a></div><div><a href="/posts/da496cff/" title="Java易错知识点汇总"><img class="cover" src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png" alt="cover"><div class="content is-center"><div class="date"><i class="far fa-calendar-alt fa-fw"></i> 2020-09-13</div><div class="title">Java易错知识点汇总</div></div></a></div></div></div><hr/><div id="post-comment"><div class="comment-head"><div class="comment-headline"><i class="fas fa-comments fa-fw"></i><span> 评论</span></div></div><div class="comment-wrap"><div><div id="twikoo-wrap"></div></div></div></div></div><div class="aside-content" id="aside-content"><div class="card-widget card-info"><div class="is-center"><div class="avatar-img"><img src= "" data-lazy-src="https://s2.loli.net/2022/08/20/hk9Zvq4YRsIcnrw.jpg" onerror="this.onerror=null;this.src='/img/friend_404.gif'" alt="avatar"/></div><div class="author-info__name">樱桃先生</div><div class="author-info__description">樱桃先生的博客小站</div></div><div class="card-info-data site-data is-center"><a href="/archives/"><div class="headline">文章</div><div class="length-num">78</div></a><a href="/tags/"><div class="headline">标签</div><div class="length-num">65</div></a><a href="/categories/"><div class="headline">分类</div><div class="length-num">21</div></a></div><a id="card-info-btn" target="_blank" rel="noopener" href="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/typoraWechat.jpeg"><i class="fab fa-weixin"></i><span>加为好友</span></a></div><div class="card-widget card-announcement"><div class="item-headline"><i class="fas fa-bullhorn fa-shake"></i><span>公告</span></div><div class="announcement_content">欢迎光临樱桃小窝🍒～评论系统日常崩溃，没有找到长期稳定好用的组件。</div></div><div class="sticky_layout"><div class="card-widget" id="card-toc"><div class="item-headline"><i class="fas fa-stream"></i><span>目录</span><span class="toc-percentage"></span></div><div class="toc-content"><ol class="toc"><li class="toc-item toc-level-1"><a class="toc-link" href="#Java%E5%B8%B8%E8%A7%81%E9%9B%86%E5%90%88%E7%B1%BB%E5%9E%8B%E5%AF%B9%E6%AF%94"><span class="toc-number">1.</span> <span class="toc-text">Java常见集合类型对比</span></a><ol class="toc-child"><li class="toc-item toc-level-2"><a class="toc-link" href="#List-%E5%92%8C-Set-%E5%8C%BA%E5%88%AB"><span class="toc-number">1.1.</span> <span class="toc-text">List 和 Set 区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#List-%E5%92%8C-Map-%E5%8C%BA%E5%88%AB"><span class="toc-number">1.2.</span> <span class="toc-text">List 和 Map 区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#ArrayList-%E4%B8%8E-LinkedList-%E5%8C%BA%E5%88%AB"><span class="toc-number">1.3.</span> <span class="toc-text">ArrayList 与 LinkedList 区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#ArrayList-%E4%B8%8E-Vector-%E5%8C%BA%E5%88%AB"><span class="toc-number">1.4.</span> <span class="toc-text">ArrayList 与 Vector 区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#HashMap-%E5%92%8C-HashTable-%E7%9A%84%E5%8C%BA%E5%88%AB"><span class="toc-number">1.5.</span> <span class="toc-text">HashMap 和 HashTable 的区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#HashSet-%E5%92%8C-HashMap-%E5%8C%BA%E5%88%AB"><span class="toc-number">1.6.</span> <span class="toc-text">HashSet 和 HashMap 区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#HashMap-%E5%92%8C-ConcurrentHashMap-%E7%9A%84%E5%8C%BA%E5%88%AB"><span class="toc-number">1.7.</span> <span class="toc-text">HashMap 和 ConcurrentHashMap 的区别</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#HashMap-%E7%9A%84%E5%B7%A5%E4%BD%9C%E5%8E%9F%E7%90%86%E5%8F%8A%E4%BB%A3%E7%A0%81%E5%AE%9E%E7%8E%B0"><span class="toc-number">1.8.</span> <span class="toc-text">HashMap 的工作原理及代码实现</span></a></li><li class="toc-item toc-level-2"><a class="toc-link" href="#ConcurrentHashMap-%E7%9A%84%E5%B7%A5%E4%BD%9C%E5%8E%9F%E7%90%86%E5%8F%8A%E4%BB%A3%E7%A0%81%E5%AE%9E%E7%8E%B0"><span class="toc-number">1.9.</span> <span class="toc-text">ConcurrentHashMap 的工作原理及代码实现</span></a></li></ol></li></ol></div></div><div class="card-widget card-recent-post"><div class="item-headline"><i class="fas fa-history"></i><span>最新文章</span></div><div class="aside-list"><div class="aside-list-item"><a class="thumbnail" href="/posts/4995/" title="顺德好友小聚"><img src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/blog-common.png" onerror="this.onerror=null;this.src='/img/404.jpg'" alt="顺德好友小聚"/></a><div class="content"><a class="title" href="/posts/4995/" title="顺德好友小聚">顺德好友小聚</a><time datetime="2023-05-07T13:41:30.660Z" title="更新于 2023-05-07 21:41:30">2023-05-07</time></div></div><div class="aside-list-item"><a class="thumbnail" href="/posts/51438/" title="旅游归来的周末"><img src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/blog-common.png" onerror="this.onerror=null;this.src='/img/404.jpg'" alt="旅游归来的周末"/></a><div class="content"><a class="title" href="/posts/51438/" title="旅游归来的周末">旅游归来的周末</a><time datetime="2023-05-06T06:06:54.933Z" title="更新于 2023-05-06 14:06:54">2023-05-06</time></div></div><div class="aside-list-item"><a class="thumbnail" href="/posts/34851/" title="与好友的广西之旅"><img src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/blog-common.png" onerror="this.onerror=null;this.src='/img/404.jpg'" alt="与好友的广西之旅"/></a><div class="content"><a class="title" href="/posts/34851/" title="与好友的广西之旅">与好友的广西之旅</a><time datetime="2023-05-02T08:08:36.497Z" title="更新于 2023-05-02 16:08:36">2023-05-02</time></div></div><div class="aside-list-item"><a class="thumbnail" href="/posts/36794/" title="信用卡业务汇总"><img src= "" data-lazy-src="https://s2.loli.net/2022/08/22/kpfRHFaCWDTNAu1.png" onerror="this.onerror=null;this.src='/img/404.jpg'" alt="信用卡业务汇总"/></a><div class="content"><a class="title" href="/posts/36794/" title="信用卡业务汇总">信用卡业务汇总</a><time datetime="2023-05-02T06:30:21.691Z" title="更新于 2023-05-02 14:30:21">2023-05-02</time></div></div><div class="aside-list-item"><a class="thumbnail" href="/posts/53652/" title="项目管理笔记"><img src= "" data-lazy-src="https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/blog-common.png" onerror="this.onerror=null;this.src='/img/404.jpg'" alt="项目管理笔记"/></a><div class="content"><a class="title" href="/posts/53652/" title="项目管理笔记">项目管理笔记</a><time datetime="2023-05-02T06:29:26.948Z" title="更新于 2023-05-02 14:29:26">2023-05-02</time></div></div></div></div></div></div></main><footer id="footer" style="background-image: url('https://ytblogpic.oss-cn-guangzhou.aliyuncs.com/Java-cover.png')"><div id="footer-wrap"><div class="copyright">&copy;2020 - 2023 By 樱桃先生</div><div class="footer_custom_text">一切都是最好的安排</div></div></footer></div><div id="rightside"><div id="rightside-config-hide"><button id="readmode" type="button" title="阅读模式"><i class="fas fa-book-open"></i></button><button id="darkmode" type="button" title="浅色和深色模式转换"><i class="fas fa-adjust"></i></button><button id="hide-aside-btn" type="button" title="单栏和双栏切换"><i class="fas fa-arrows-alt-h"></i></button></div><div id="rightside-config-show"><button id="rightside_config" type="button" title="设置"><i class="fas fa-cog fa-spin"></i></button><button class="close" id="mobile-toc-button" type="button" title="目录"><i class="fas fa-list-ul"></i></button><a id="to_comment" href="#post-comment" title="直达评论"><i class="fas fa-comments"></i></a><button id="go-up" type="button" title="回到顶部"><i class="fas fa-arrow-up"></i></button></div></div><div><script src="/js/utils.js"></script><script src="/js/main.js"></script><script src="https://cdn.jsdelivr.net/npm/@fancyapps/ui/dist/fancybox.umd.min.js"></script><script src="https://cdn.jsdelivr.net/npm/vanilla-lazyload/dist/lazyload.iife.min.js"></script><div class="js-pjax"><script>(()=>{
  const init = () => {
    twikoo.init(Object.assign({
      el: '#twikoo-wrap',
      envId: 'https://twikoo-seven-fawn.vercel.app',
      region: '',
      onCommentLoaded: function () {
        btf.loadLightbox(document.querySelectorAll('#twikoo .tk-content img:not(.tk-owo-emotion)'))
      }
    }, null))
  }

  const getCount = () => {
    const countELement = document.getElementById('twikoo-count')
    if(!countELement) return
    twikoo.getCommentsCount({
      envId: 'https://twikoo-seven-fawn.vercel.app',
      region: '',
      urls: [window.location.pathname],
      includeReply: false
    }).then(function (res) {
      countELement.innerText = res[0].count
    }).catch(function (err) {
      console.error(err);
    });
  }

  const runFn = () => {
    init()
    
  }

  const loadTwikoo = () => {
    if (typeof twikoo === 'object') {
      setTimeout(runFn,0)
      return
    } 
    getScript('https://cdn.jsdelivr.net/npm/twikoo/dist/twikoo.all.min.js').then(runFn)
  }

  if ('Twikoo' === 'Twikoo' || !true) {
    if (true) btf.loadComment(document.getElementById('twikoo-wrap'), loadTwikoo)
    else loadTwikoo()
  } else {
    window.loadOtherComment = () => {
      loadTwikoo()
    }
  }
})()</script></div><script>window.addEventListener('load', () => {
  const changeContent = (content) => {
    if (content === '') return content

    content = content.replace(/<img.*?src="(.*?)"?[^\>]+>/ig, '[图片]') // replace image link
    content = content.replace(/<a[^>]+?href=["']?([^"']+)["']?[^>]*>([^<]+)<\/a>/gi, '[链接]') // replace url
    content = content.replace(/<pre><code>.*?<\/pre>/gi, '[代码]') // replace code
    content = content.replace(/<[^>]+>/g,"") // remove html tag

    if (content.length > 150) {
      content = content.substring(0,150) + '...'
    }
    return content
  }

  const getComment = () => {
    const runTwikoo = () => {
      twikoo.getRecentComments({
        envId: 'https://twikoo-seven-fawn.vercel.app',
        region: '',
        pageSize: 6,
        includeReply: true
      }).then(function (res) {
        const twikooArray = res.map(e => {
          return {
            'content': changeContent(e.comment),
            'avatar': e.avatar,
            'nick': e.nick,
            'url': e.url + '#' + e.id,
            'date': new Date(e.created).toISOString()
          }
        })

        saveToLocal.set('twikoo-newest-comments', JSON.stringify(twikooArray), 10/(60*24))
        generateHtml(twikooArray)
      }).catch(function (err) {
        const $dom = document.querySelector('#card-newest-comments .aside-list')
        $dom.innerHTML= "无法获取评论，请确认相关配置是否正确"
      })
    }

    if (typeof twikoo === 'object') {
      runTwikoo()
    } else {
      getScript('https://cdn.jsdelivr.net/npm/twikoo/dist/twikoo.all.min.js').then(runTwikoo)
    }
  }

  const generateHtml = array => {
    let result = ''

    if (array.length) {
      for (let i = 0; i < array.length; i++) {
        result += '<div class=\'aside-list-item\'>'

        if (true) {
          const name = 'data-lazy-src'
          result += `<a href='${array[i].url}' class='thumbnail'><img ${name}='${array[i].avatar}' alt='${array[i].nick}'></a>`
        }
        
        result += `<div class='content'>
        <a class='comment' href='${array[i].url}' title='${array[i].content}'>${array[i].content}</a>
        <div class='name'><span>${array[i].nick} / </span><time datetime="${array[i].date}">${btf.diffDate(array[i].date, true)}</time></div>
        </div></div>`
      }
    } else {
      result += '没有评论'
    }

    let $dom = document.querySelector('#card-newest-comments .aside-list')
    $dom.innerHTML= result
    window.lazyLoadInstance && window.lazyLoadInstance.update()
    window.pjax && window.pjax.refresh($dom)
  }

  const newestCommentInit = () => {
    if (document.querySelector('#card-newest-comments .aside-list')) {
      const data = saveToLocal.get('twikoo-newest-comments')
      if (data) {
        generateHtml(JSON.parse(data))
      } else {
        getComment()
      }
    }
  }

  newestCommentInit()
  document.addEventListener('pjax:complete', newestCommentInit)
})</script><script src="/js/jquery.min.js"></script><div class="aplayer no-destroy" data-id="5225697049" data-server="netease" data-type="playlist" data-fixed="true" data-autoplay="false" data-mini="true" data-lrctype="-1"> </div><script src="https://cdn.jsdelivr.net/gh/xiabo2/CDN@latest/fishes.js"></script><link rel="stylesheet" href="/css/utils.css"><script defer="defer" id="ribbon" src="https://cdn.jsdelivr.net/npm/butterfly-extsrc/dist/canvas-ribbon.min.js" size="150" alpha="0.6" zIndex="-1" mobile="false" data-click="true"></script><link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/aplayer/dist/APlayer.min.css" media="print" onload="this.media='all'"><script src="https://cdn.jsdelivr.net/npm/aplayer/dist/APlayer.min.js"></script><script src="https://cdn.jsdelivr.net/npm/butterfly-extsrc/metingjs/dist/Meting.min.js"></script><script src="https://cdn.jsdelivr.net/npm/pjax/pjax.min.js"></script><script>let pjaxSelectors = ["head > title","#config-diff","#body-wrap","#rightside-config-hide","#rightside-config-show",".js-pjax"]

var pjax = new Pjax({
  elements: 'a:not([target="_blank"])',
  selectors: pjaxSelectors,
  cacheBust: false,
  analytics: false,
  scrollRestoration: false
})

document.addEventListener('pjax:send', function () {

  // removeEventListener scroll 
  window.tocScrollFn && window.removeEventListener('scroll', window.tocScrollFn)
  window.scrollCollect && window.removeEventListener('scroll', scrollCollect)

  typeof preloader === 'object' && preloader.initLoading()
  document.getElementById('rightside').style.cssText = "opacity: ''; transform: ''"
  
  if (window.aplayers) {
    for (let i = 0; i < window.aplayers.length; i++) {
      if (!window.aplayers[i].options.fixed) {
        window.aplayers[i].destroy()
      }
    }
  }

  typeof typed === 'object' && typed.destroy()

  //reset readmode
  const $bodyClassList = document.body.classList
  $bodyClassList.contains('read-mode') && $bodyClassList.remove('read-mode')

  typeof disqusjs === 'object' && disqusjs.destroy()
})

document.addEventListener('pjax:complete', function () {
  window.refreshFn()

  document.querySelectorAll('script[data-pjax]').forEach(item => {
    const newScript = document.createElement('script')
    const content = item.text || item.textContent || item.innerHTML || ""
    Array.from(item.attributes).forEach(attr => newScript.setAttribute(attr.name, attr.value))
    newScript.appendChild(document.createTextNode(content))
    item.parentNode.replaceChild(newScript, item)
  })

  GLOBAL_CONFIG.islazyload && window.lazyLoadInstance.update()

  typeof chatBtnFn === 'function' && chatBtnFn()
  typeof panguInit === 'function' && panguInit()

  // google analytics
  typeof gtag === 'function' && gtag('config', '', {'page_path': window.location.pathname});

  // baidu analytics
  typeof _hmt === 'object' && _hmt.push(['_trackPageview',window.location.pathname]);

  typeof loadMeting === 'function' && document.getElementsByClassName('aplayer').length && loadMeting()

  // prismjs
  typeof Prism === 'object' && Prism.highlightAll()

  typeof preloader === 'object' && preloader.endLoading()
})

document.addEventListener('pjax:error', (e) => {
  if (e.request.status === 404) {
    pjax.loadUrl('/404.html')
  }
})</script><script async data-pjax src="//busuanzi.ibruce.info/busuanzi/2.3/busuanzi.pure.mini.js"></script></div><script src="/live2dw/lib/L2Dwidget.min.js?094cbace49a39548bed64abff5988b05"></script><script>L2Dwidget.init({"model":{"jsonPath":"/live2dw/assets/hijiki.model.json"},"display":{"position":"right","width":170,"height":280},"mobile":{"show":true},"log":false,"pluginJsPath":"lib/","pluginModelPath":"assets/","pluginRootPath":"live2dw/","tagMode":false});</script></body></html>